There's a few guaranteed things in life. There's life, death, and gravity. Everyone who lives will eventually die. And sadly while some lives mere minutes, one of the only other guaranteed things is gravity. It takes effect on us all, every minute, of every day for the entire duration of our lives.
While everyone is impacted by Mean Ol' Mister Gravity, some people have a bad relationship with him and others a great relationship. Another way I've heard this explained is via the question "What is your relationship with the floor?" In regards to those pursuing athletic endeavors, this question needs to a positive answer.
When considering the development of athletes, we need to remember that the ability to defy and utilize gravity is essential to dominant performance. The ability to reach high, get low, accelerate, and decelerate is important in any form of offense or defense. And while this process naturally starts at birth, at a certain point many people stop growing because the stop challenging their abilities and keep the base abilities they have: walking, laying, sitting, kneeling, etc.
The abilities of an athlete need to be progressed to an extent that surpasses the normal population's. While the progress for many slows significantly after walking and jogging, it demands a continued nurturing in order to build greater general athletic qualities. Rolling, crawling, jumping, and landing, are all ground based movements that are indicative of athletic ability. While we do this initially as infants, there are always ways to progress these movements to be more difficult and challenging.
For example, rolling from side to side while lying prone develops core strength and the neural capacity to create and resist rotation. While rolling on the floor is elementary, we can progress this to rolling from hand to hand, creating a higher demand for the core stability, rotational and anti-rotational ability, and then adds shoulder strength and stability.
Similarly, crawling produces a neural stimulus by creating cross body movement and coordination. It also creates anti-rotational demands with the demands of balance. After learning to walk, crawling seems simple. But like the roll, take away some of the surface
contact with the ground and it increases it difficulty. In my own coaching, I've seen many young children (7-13) barely be able to crawl 10 yards when they had to do so with their knees an inch off the ground during what is known as a leopard crawl. From there, crawling can be made even tougher with some creativity and differing variations (ask your athletes to crawl backward for some amusement).
Personally, I like to introduce odd ground based movements and movement combinations to challenge athletes in various ways. While performing an isolated movement may present a challenge to the young athlete (6-10), other athletes require an additional challenge by creating movement sequences. While a prone roll is easy, a hand to hand roll-to-bridge with only one foot on the ground provides a nice challenge for most. More advanced ground based movements such as a sit-through, bear squat, or various pushup movements are a great way to strengthen new positions and develop a better relationship with the ground.
Two great things that can also come from these types of movements is the spacial awareness and practicality they produce. On the practical side, ground based movements just need some floor space and creativity. The amount of space you utilize, then impacts the spacial awareness of the athlete doing the movements (or yourself). You learn to use the area you are given and whatever else occupies it, creating the awareness of your limbs and physical ability.
And while ground based movement is essential, it is simply a component of building an athletic base on which greater skills and strengths can be built on. Especially as athletes mature and develop, the need for developing these ground based movements decreases as focus on specific skill development and specific strength adaptations increases. While a great tool for building a general athletic base for young or beginner athletes, the more developed an athlete gets the less needed they become.